title: Microbial dechlorination activity during and after chemical oxidant treatment.
abstract: Potassium permanganate (PM) and sodium persulfate (PS) are used in soil remediation, however, their compatibility with a coinciding or subsequent biotreatment is poorly understood. In this study, different concentrations of PM (0.005-2g/L) and PS (0.01-4.52 g/L) were applied and their effects on the abundance, activity, and reactivation potential of a dechlorinating enrichment culture were investigated. Expression of the tceA, vcrA and 16S rRNA genes of Dehalococcoides spp. were detected at 0.005-0.01 g/L PM and 0.01-0.02 g/L PS. However, with 0.5-2g/L PM and 1.13-4.52 g/L PS no gene expression was recorded, neither were indicator molecules for total cell activity (Adenosine triphosphate, ATP) detected. Dilution did not promote the reactivation of the microbial cells when the redox potential was above -100 mV. Similarly, inoculated cells did not dechlorinate trichloroethene (TCE) above -100 mV. When the redox potential was decreased to -300 mV and the reactors were bioaugmented for a second time, dechlorination activity recovered, but only in the reactors with 1.13 and 2.26 g/L PS. In conclusion, our results show that chemical oxidants can be combined with a biotreatment at concentrations below 0.5 g/L PM and 1g/L PS.
authors.affiliation: Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium; Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Eylem
authors.initials: E
authors.lastname: Doğan-Subaşı
authors.forename: Leen
authors.initials: L
authors.lastname: Bastiaens
authors.forename: Nico
authors.initials: N
authors.lastname: Boon
authors.forename: Winnie
authors.initials: W
authors.lastname: Dejonghe
mesh_terms: D041862:Chloroflexi / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D018628:Gene Dosage; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D011196:Potassium Permanganate / Q000494:pharmacology*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017670:Sodium Compounds / Q000494:pharmacology*; D012989:Soil Pollutants / Q000378:metabolism*; D013431:Sulfates / Q000494:pharmacology*; D014241:Trichloroethylene / Q000378:metabolism*
chemical_list: D016877:Oxidants; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D017670:Sodium Compounds; D012989:Soil Pollutants; D013431:Sulfates; D011196:Potassium Permanganate; D014241:Trichloroethylene; C024625:sodium persulfate
keywords: Oxidation; Permanganate; Persulfate; RDase genes; Recovery; mRNA